Disposable forceps

ABSTRACT

Disposable forceps are molded from a suitable sterilizable plastic material and they have a pair of arms joined together at inner ends by a hinge section of reduced cross-section so that outer sections of the arms are disposed substantially parallel to each other when the arms are in their normally inoperative position. When the arms are operated, the outer ends of the teeth engage before or simultaneously with the engagement of the innermost ends of the strengthening ribs. Alignment lugs are provided on an inside surface of each arm which have mateable surfaces to prevent any transverse misalignment between the teeth during engagement therebetween and outer ends of the alignment lugs engage recesses in the inside surfaces of the arms to prevent overstressing and rocking of the teeth.

llnited States Patent Shannon [451 Apr. 4, 1972 [54] DISPOSABLE FORCEPS[72] inventor: Suel Grant Shannon, Harrisburg, Pa. [73] Assignee: AMPIncorporated, Harrisburg, Pa. [22] Filed: Jan. 19,- 1970 21 AppL No.:3,682

52 us. Cl ..12s/3s4, 81/43 Holohan ..128/321 Primary Examiner-ChanningL. Pace AttorneyCurtis, Morris and Safford, William J. Keating, RonaldD. Grefe, William l-lintze, Adrian J. La Rue, Frederick W. Rating, JayL. Seitchik and John P. Vandenburg [5 7] ABSTRACT Disposable forceps aremolded from a suitable sterilizable plastic material and they have apair of arms joined together at inner ends by a hinge section of reducedcross-section so that outer sections of the arms are disposedsubstantially parallel to each other when the arms are in their normallyinoperative position. When the arms are operated, the outer ends of theteeth engage before or simultaneously with the engagement of theinnermost ends of the strengthening ribs. Alignment lugs are provided onan inside surface of each arm which have mateable surfaces to preventany transverse misalignment between the teeth during engagementtherebetween and outer ends of the alignment lugs engage recesses in theinside surfaces of the arms to prevent overstressing and rocking of theteeth.

6 Claims, 6 Drawing Figures Patented April 4, 1972 3fi3389 INVENTOR SUELGRANT SHANNON DISPOSAIBLE FORCEPS This invention relates to forceps andmore particularly to improved forceps molded from suitable sterilizableplastic materials.

Plastic forceps are known since they are readily molded fromsterilizable plastic material and they are capable of being discardedafter use due to the fact that they can be manufactured for low cost.

Conventional forceps are in widespread use in hospitals, clinics anddoctorss offices because they can be economically marketed as apresterilized package for a one-time use to remove sutures, handledressings, hold cotton to swab areas of a patient and other medicaluses. The forceps can, of course, be resterilized for reuse if desired.

One drawback of these conventional plastic forceps is that the areasadjacent the hinge point have the same thickness as or a thicknessgreater than the arms which require relatively high initial actuatingforces to be exerted on the arms. Another drawback is that the innerends of the strengthening ribs engage one another prior to thearticle-engaging teeth engaging each other and this does not permiteffectively engaging an article at the initial engagement of the teeth.A further drawback is that the teeth do not transversely align prior toengagement, which of course, makes it difficult to grasp small items. Anadditional drawback is the fact that the strengthening ribs haveopenings therein as part of the aligning means which weakens the armsofthe forceps.

An object of the present invention is to provide plastic forceps havingsections of reduced thickness adjacent the hinged point so that lowpinching forces are required on the arms for initial closure.

Another object is the provision of outer ends of article-engaging teethof the forceps engaging one another prior to or simultaneously with theinner ends of strengthening ribs engaging each other so that an articlecan be grasped with a minimum of effort.

A further object is to provide aligning lugs to transversely align thearticle-engaging teeth just prior to the outer ends of the teethengaging each other.

An additional object is the provision of the aligning lugs assuring thatthere is proper axial alignment of the article-engaging teeth.

Still a further object is the provision that the aligning lugs definestop means to limit the pressure that the article-engaging teeth exerton each other.

A still further object is to provide aligning lugs of the forceps whichwill prevent any rocking motion of the article-engaging teeth.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon a reading of the followingdetailed description when taken in conjunction with the drawings inwhich there is shown and described an i1- lustrative embodiment of theinvention; it is to be understood, however, that this embodiment is notintended to be exhaustive nor limiting of the invention but is given forpurpose of illustration in order that others skilled in the art mayfully understand the invention and the principles thereof and the mannerof applying it in practical use so that they may modify it in variousforms, each as may be best suited to the conditions of a particular use.

IN THE DRAWINGS FIG. 1 is a perspective view of a pair of forceps in itsoriginally molded and therefore normally inoperative position;

FIG. 2 is a side elevational view of the forceps of FIG. 1;

FIG. 3 is a view similar to FIG. 2 with the forceps at the initialengagement of the article-engaging teeth when pinching forces areapplied to the arms;

FIG. 4 is a view similar to FIG. 3 illustrating the forceps when thearticle-engaging teeth are fully closed;

FIG. 5 is a view taken along line 5-5 ofFIG. 2; and

FIG. 6 is a view taken along lines 6-6 of FIG. 4.

Turning now to the drawing, forceps F are provided with arms 1 which areconnected together at inner ends by a connecting section 2. Each arm 1is provided with a hinge section 3, an inclined section 4, a straightsection 5 and article-engaging teeth 6. Straight sections 5 taper fromsections 4 to the outer ends of the arms. Strengthening ribs 7 areprovided on the inside surfaces of sections 4 and 5 to strengthen arms 1and inner and outer alignment lugs 8 and 9 are disposed adjacentarticle-engaging teeth 6. Strengthening ribs 7 in the area of lugs 8 and9 have a sinusoidal configuration and this permits the strengtheningribs to extend from hinge sections 3 along sections 4 and 5 witharticle-engaging teeth 6 being disposed in opposing surfaces of ribs 7.

Lugs 8 and 9 on each arm 1 are axially displaced with respect to eachother and also disposed on opposite sides of a medium plane asillustrated in FIG. 5. The alignment lugs 8 and 9 have their innerradiused and angular lead-in surfaces at outer ends thereof which mergeinto straight guide surfaces to provide the alignment of the teeth, andthe lugs engage prior to the teeth 6 engaging to provide the necessarytransverse alignment of the teeth as the angular lead-in surfaces of theouter lugs 9 engage each other; axial alignment of the teeth 6 isaccomplished during engagement between the outer arcuate ends of thelugs and arcuate recesses 10 in which these outer arcuate ends aredisposed.

Lugs 8 and 9 align the teeth in a transverse direction and the lugs andarcuate recesses 10 in which arcuate ends of lugs 8 and 9 are receivedalign the article-engaging teeth in an axial direction. Thearticle-engaging teeth 6 cannot be misaligned as a result of the actionof the aligning lugs 8 and 9 under normal gripping pressure. Moreover,arcuate ends of lugs 8 and 9 and arcuate recesses 10 define stop meansto limit the pressure teeth 6 exert on each other and also to insurecomplete engagement therealong. The forward stop means constitutingouter radiused ends of lugs 9 and arcuate recesses 10 in which they mateprevent any rocking motion of teeth 6 when teeth 6 are fully engagedalong their length as illustrated in FIG. 4

Hinged sections 3 are not as thick as inclined sections 4 and straightsections 5 to provide ease of closure of the forceps and to permitbowing out when pressure at an inner pivot point, which is provided bythe inner ends of strengthening ribs 7, reaches a stress conditionthereby providing compensation to prevent the hinged sections frombreaking.

The tips of article-engaging teeth 6 can engage as illustrated in FIG. 3prior to or simultaneously with the engagement of the inner ends ofstrengthening ribs 7 so that no excessive pressure is needed to bringteeth 6 into initial engagement and the transverse and axial alignmentof teeth 6 are accomplished by alignment lugs 8 and 9 to assure thepositive engagement of an article by article-engaging teeth 6.

The initial engagement of teeth 6, when arms 1 are moved toward oneanother as illustrated in FIG. 3, is such that sections 5 and all ofteeth 6 except the outer ones in engagement are disposed at an angulardisposition with respect to each other so that further pressure onsections 5 cause the angular disposition to decrease until all of theteeth are in engagement as illustrated in FIG. 4, and the inner pivotpoint at the inner ends of strengthening ribs 7 when the inner ends arein engagement causes the hinge sections to begin their bowing outfunction which allows the proper amount of gripping pressure to beapplied to the teeth and this action removes the effect of the hingesections on the pressure being applied to the teeth. The engagement ofthe inner ends of the strengthening ribs shortens the working length ofthe arms.

Ribs 1 1 are disposed along the outer surfaces of straight sections 5 toprovide engaging areas for an operator to normally engage the forcepsbetween the thumb and forefinger of an operator so that the ribbed areabetween lugs 8 and the junctions between sections 4 and 5 definegrasping areas for normally grasping the forceps to operate same.

The angular configuration of inclined sections 4 is such that one wouldnot normally handle the forceps here to operate the forceps but wouldnormally handle the forceps along the ribbed areas of sections 5 whichrepresents the optimum area for operating the forceps. The ribbed area,of course, facilitates handling of the forceps. The pivot point at theinnermost ends of strengthening ribs 7 is formed when these innermostends are moved into engagement prior to or simultaneously with theengagement of the article-engaging teeth 6 to limit the degree of pivotand to provide a point to permit the teeth to mesh completely aspressure is being applied to the arms. The innermost ends of ribs 7 maybe provided with projections to assure that these come together at thesame time the outermost teeth engage. The forceps are incapable of beingbroken by normal finger pressure.

The forceps are molded in accordance with normal molding techniques froma suitable plastic material that can be sterilized such as, for example,glass-filled nylon, and the forceps is molded as illustrated in FIGS. 1and 2 with the straight sections and article-engaging teeth beingdisposed substantially parallel with respect to each other which is anormally inoperative position and the forceps are now ready to beoperated.

It will, therefore, be appreciated that the afore-mentioned and otherdesirable objects have been achieved; however, it should be emphasizedthat the particular embodiment of the invention, which is shown anddescribed herein, is intended as merely illustrative and not asrestrictive of the invention.

The invention is claimed in accordance with the following:

1. In a forceps having a pair of elongated arms projectinglongitudinally from a unitary connecting section, with tips adjacent tothe free ends of said arms being engageable upon pivotal action of saidarms toward each other, the combination comprising:

a pair of diverging portions of said arms projecting longitudinally fromsaid connecting section,

a pair of elongated straight sections unitary with and projectinglongitudinally from said corresponding diverging portions, each of saiddiverging portions including a first flexible hinge section ofrelatively thin cross-section immediately adjacent to the connectingsection, each ofsaid diverging portions further including a secondrelatively thick section unitary with and immediately adjacent to acorresponding flexible hinge section, said elongated arms being providedwith corresponding elongated strengthening ribs, each of said ribsprojecting laterally from and unitary with said relatively thick sectionand said elongated straight section of a corresponding arm, each of saidribs having a first end terminating at said relatively thin hingesection of a corresponding arm to prevent strengthening of said hingesection, each of said ribs having a second end projecting longitudinallybeyond a free end of a corresponding arm to define one of said tips, andsaid tips of said ribs being provided with teeth, and said tips of saidribs being provided with teeth, which teeth are interengageable uponflexing of said hinge sections to allow pivotal action of said armstoward each other, said second ends of said ribs extendinglongitudinally beyond the free ends ofsaid arms and being tapered todefine said projecting tips.

2. The structure as recited in claim 1, wherein, said first end portionsof said ribs are initially in opposed spaced relationship and areengageable with said hinge section being retained in bowed and generallydiverging relationship upon pivotal action of said arms toward eachother.

3. The structure as recited in claim 1, wherein, each of said ribs iscontinuous from its first end to its second end thereof, said ribshaving mutually opposed sinusoidal sections with a pair of lugsprotruding from each sinusoidal section and spaced longitudinally alonga corresponding rib, and said lugs of one rib overlap the correspondinglugs of the other rib upon pivotal action of said arms toward eachother.

4. The structure as recited in claim 3, wherein said sinusoidal sectionof each rib is located along said straight section of a correspondingarm, said straight section is provided with a pair of generally arcuaterecesses on opposite sides of said rib at the sinusoidal sectionsthereof, and each pair oflugs is provided with a generally arcuate endportion for mating registration within corresponding arcuate recesses toprevent any rocking motion of said interengaged teeth and to define stopmeans for limiting the pressure between said interengaged teeth.

5. The structure as recited in claim 1, wherein, said first ends of saidribs are engageable to define a secondary pivot point for said arms, andthereby shorten the effective working pivotal length of said amis,

6. The structure as recited in claim 1, wherein, said first end portionsof said ribs are initially in opposed spaced relationship and areengageable with said hinge section being retained in bowed and generallydiverging relationship upon pivotal action of said arms toward eachother, and wherein, said first ends of said ribs are engageable todefine a secondary pivot point for said arms, and thereby shorten theeffective working pivotal length of said arms.

1. In a forceps having a pair of elongated arms projectinglongitudinally from a unitary connecting section, with tips adjacent tothe free ends of said arms being engageable upon pivotal action of saidarms toward each other, the combination comprising: a pair of divergingportions of said arms projecting longitudinally from said connectingsection, a pair of elongated straight sections unitary with andprojecting longitudinally from said corresponding diverging portions,each of said diverging portions including a first flexible hinge sectionof relatively thin cross-section immediately adjacent to the connectingsection, each of said diverging portions further including a secondrelatively thiCk section unitary with and immediately adjacent to acorresponding flexible hinge section, said elongated arms being providedwith corresponding elongated strengthening ribs, each of said ribsprojecting laterally from and unitary with said relatively thick sectionand said elongated straight section of a corresponding arm, each of saidribs having a first end terminating at said relatively thin hingesection of a corresponding arm to prevent strengthening of said hingesection, each of said ribs having a second end projecting longitudinallybeyond a free end of a corresponding arm to define one of said tips, andsaid tips of said ribs being provided with teeth, and said tips of saidribs being provided with teeth, which teeth are interengageable uponflexing of said hinge sections to allow pivotal action of said armstoward each other, said second ends of said ribs extendinglongitudinally beyond the free ends of said arms and being tapered todefine said projecting tips.
 2. The structure as recited in claim 1,wherein, said first end portions of said ribs are initially in opposedspaced relationship and are engageable with said hinge section beingretained in bowed and generally diverging relationship upon pivotalaction of said arms toward each other.
 3. The structure as recited inclaim 1, wherein, each of said ribs is continuous from its first end toits second end thereof, said ribs having mutually opposed sinusoidalsections with a pair of lugs protruding from each sinusoidal section andspaced longitudinally along a corresponding rib, and said lugs of onerib overlap the corresponding lugs of the other rib upon pivotal actionof said arms toward each other.
 4. The structure as recited in claim 3,wherein said sinusoidal section of each rib is located along saidstraight section of a corresponding arm, said straight section isprovided with a pair of generally arcuate recesses on opposite sides ofsaid rib at the sinusoidal sections thereof, and each pair of lugs isprovided with a generally arcuate end portion for mating registrationwithin corresponding arcuate recesses to prevent any rocking motion ofsaid interengaged teeth and to define stop means for limiting thepressure between said interengaged teeth.
 5. The structure as recited inclaim 1, wherein, said first ends of said ribs are engageable to definea secondary pivot point for said arms, and thereby shorten the effectiveworking pivotal length of said arms.
 6. The structure as recited inclaim 1, wherein, said first end portions of said ribs are initially inopposed spaced relationship and are engageable with said hinge sectionbeing retained in bowed and generally diverging relationship uponpivotal action of said arms toward each other, and wherein, said firstends of said ribs are engageable to define a secondary pivot point forsaid arms, and thereby shorten the effective working pivotal length ofsaid arms.